The objectives of this project are to develop, adapt, expand, and evaluate methodological procedures useful in epidemiologic studies of cancer. Methods of design and analysis of epidemiologic studies were given particular emphasis with attention focusing on the adaptation and evaluation of multivariate logistic models for analysis of case-control data. Investigation of general epidemiologic techniques for studying environmental cancer continued, including publication of a text and series of papers on biostatistical methods and review of methods to evaluate the magnitude of low-dose radiation risks.